diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index 7d00211ea1..c617a0ec3b 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -2,7 +2,7 @@
 
 * Renames Array#rand -> Array#random_element. [Santiago Pastorino, Rizwan Reza]
 
-* Defines prev_(month|year) in Date and Time, and deprecates last_(month|year). [fxn]
+* 1.9 compat: Renames last_(month|year) to prev_(month|year) in Date and Time. [fxn]
 
 * Aliases Date#sunday to Date#end_of_week. [fxn]
 
diff --git a/activesupport/lib/active_support/core_ext/date/calculations.rb b/activesupport/lib/active_support/core_ext/date/calculations.rb
index 755d96ce91..579079d4f1 100644
--- a/activesupport/lib/active_support/core_ext/date/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date/calculations.rb
@@ -2,7 +2,6 @@
 require 'active_support/duration'
 require 'active_support/core_ext/time/zones'
 require 'active_support/core_ext/object/acts_like'
-require 'active_support/deprecation'
 
 class Date
   if RUBY_VERSION < '1.9'
@@ -147,11 +146,6 @@ def years_since(years)
     advance(:years => years)
   end
 
-  def last_year # :nodoc:
-    ActiveSupport::Deprecation.warn("Date#last_year has been deprecated, please use Date#prev_year instead", caller)
-    prev_year
-  end
-
   # Shorthand for years_ago(1)
   def prev_year
     years_ago(1)
@@ -161,11 +155,6 @@ def prev_year
   def next_year
     years_since(1)
   end unless method_defined?(:next_year)
-
-  def last_month # :nodoc:
-    ActiveSupport::Deprecation.warn("Date#last_month has been deprecated, please use Date#prev_month instead", caller)
-    prev_month
-  end
   
   # Short-hand for months_ago(1)
   def prev_month
diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index e27b08ec2e..3c218d88e5 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -2,7 +2,6 @@
 require 'active_support/core_ext/date/acts_like'
 require 'active_support/core_ext/date/calculations'
 require 'active_support/core_ext/date_time/conversions'
-require 'active_support/deprecation'
 
 class Time
   COMMON_YEAR_DAYS_IN_MONTH = [nil, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
@@ -133,11 +132,6 @@ def years_since(years)
     advance(:years => years)
   end
 
-  def last_year # :nodoc:
-    ActiveSupport::Deprecation.warn("Time#last_year has been deprecated, please use Time#prev_year instead", caller)
-    prev_year
-  end
-
   # Short-hand for years_ago(1)
   def prev_year
     years_ago(1)
@@ -148,11 +142,6 @@ def next_year
     years_since(1)
   end
 
-  def last_month # :nodoc:
-    ActiveSupport::Deprecation.warn("Time#last_month has been deprecated, please use Time#prev_month instead", caller)
-    prev_month
-  end
-
   # Short-hand for months_ago(1)
   def prev_month
     months_ago(1)
diff --git a/activesupport/test/core_ext/date_ext_test.rb b/activesupport/test/core_ext/date_ext_test.rb
index 1bf118e3b7..a3a2f13436 100644
--- a/activesupport/test/core_ext/date_ext_test.rb
+++ b/activesupport/test/core_ext/date_ext_test.rb
@@ -145,10 +145,6 @@ def test_years_since
     assert_equal Date.new(2005,2,28), Date.new(2004,2,29).years_since(1) # 1 year since leap day
   end
 
-  def test_last_year_is_deprecated
-    assert_deprecated { Date.today.last_year }
-  end
-
   def test_prev_year
     assert_equal Date.new(2004,6,5),  Date.new(2005,6,5).prev_year
   end
@@ -229,10 +225,6 @@ def test_next_month_on_31st
     assert_equal Date.new(2005, 9, 30), Date.new(2005, 8, 31).next_month
   end
 
-  def test_last_month_is_deprecated
-    assert_deprecated { Date.today.last_month }
-  end
-
   def test_prev_month_on_31st
     assert_equal Date.new(2004, 2, 29), Date.new(2004, 3, 31).prev_month
   end
diff --git a/activesupport/test/core_ext/time_ext_test.rb b/activesupport/test/core_ext/time_ext_test.rb
index 30ee1d1652..1cf84df386 100644
--- a/activesupport/test/core_ext/time_ext_test.rb
+++ b/activesupport/test/core_ext/time_ext_test.rb
@@ -166,10 +166,6 @@ def test_years_since
     # assert_equal Time.local(2182,6,5,10),  Time.local(2005,6,5,10,0,0).years_since(177)
   end
 
-  def test_last_year_is_deprecated
-    assert_deprecated { Time.now.last_year }
-  end
-
   def test_prev_year
     assert_equal Time.local(2004,6,5,10),  Time.local(2005,6,5,10,0,0).prev_year
   end
@@ -619,10 +615,6 @@ def test_next_month_on_31st
     assert_equal Time.local(2005, 9, 30), Time.local(2005, 8, 31).next_month
   end
 
-  def test_last_month_is_deprecated
-    assert_deprecated { Time.now.last_month }
-  end
-
   def test_prev_month_on_31st
     assert_equal Time.local(2004, 2, 29), Time.local(2004, 3, 31).prev_month
   end